- Stock: In Stock
- Model: SC21422
- Weight: 0.02kg
- Dimensions: 11.00cm x 5.00cm x 5.00cm
- SKU: SC21422
- UPC: 4012929214204
Square Recess | Robertson Bits
Square Recess Bit: No. 2 (length: 25 mm)
Packaging: 2 Pack Carded
A Robertson, also known as a square or Scrulox screw drive is specified as ANSI Type III Square Centre and has a square-shaped socket in the screw head and a square protrusion on the tool. Both the tool and the socket have a slight taper.
As patents expired and awareness of their advantages spread, Robertson fasteners have become popular in woodworking and in general construction. Robertson screw bits are easy to use one-handed, because the tapered socket tends to retain the screw, even if it is shaken.
Universal hexagonal shaft in 6,35 mm (¼ inch)
From Wikipedia
Robertson had licensed the screw design to a maker in England, but the party that he was dealing with intentionally drove the licensee company into bankruptcy and purchased the rights at a reduced price from the trustee, thus circumventing the original agreement.
Robertson spent a small fortune buying back the rights, and subsequently refused to allow anyone else to make the screws under license. When Henry Ford tried out the Robertson screws, he found that they saved considerable time in Model T production, but when Robertson refused to license the screw design, Ford realized that the supply of screws would not be guaranteed and chose to limit their use in production to Ford's Canadian division.
Robertson's refusal to license his screws prevented their widespread adoption in the United States, where the more widely-licensed Phillips head gained wider acceptance. The restriction of licensing of Robertson's internal-wrenching square may have sped the development of the internal-wrenching hexagon, although documentation of this is limited.
Features
Based on the Standard Bit, the other bits are optimized by means of various hardening and coating methods. It provides a consistent hardness of ~700HV and features a highly accurate fit in the screw.
The Classic Robertson Bit is hardened using a special procedure. The tough version resulting from this method meets the demands across all areas of industry and craft.
- Security applications
- One-handed use
- Accurate fit in screw head
- Specific driver for each diameter fastener
- ¼ inch drive
- Available in different packaging and quantities